LOLE and EDNS calculation in presence of RES, pump units and interconnections

This paper presents the solutions adopted by Red Electrica de Espana (REE) in its software, E-LOLA, developed with the main purpose of calculating the probabilistic generation adequacy indices LOLE — Loss Of Load Expectation — and EDNS — Expected Demand Not Supplied — for the 10 Spanish isolated electric systems, making it possible to assess system adequacy through a non-deterministic approach. Based on previous research [1], the authors developed new methodologies for Renewable Energy Sources (RES), pump units and interconnections for the calculation of LOLE and EDNS. The probabilistic consideration of RES is based on synthetic series using Markov Chain (MCh) methodology and Monte Carlo Simulation (MCS). The treatment of pump units is based on a novel in-house methodology which authors named "best use". This methodology consists in a use of the pump units aimed at optimizing the above mentioned indices. The probabilistic support of the interconnections is also based in a novel in-house methodology improving the previous work, and allowing more than two interconnections between isolated systems with any configuration. This paper explains in detail the new methodologies developed by REE to assess generation adequacy in isolated systems in a new environment, and presents the results obtained with the new tool E-LOLA developed for this purpose.